Ring clearances ???

[Brockey]

As some have read the local machine shop fooled up my 250r air fooler cylinder by boring it too much. They got a used cylinder and bored it to fit my 72 mm piston. Now I have no idea on how much clearances their has to be and have no way of checking it really. I just put a ring in my replacement cylinder and it seems to almost close up the ring all together. I could get about 2 sheets of paper between the ends of the ring.
Now they gave me back my old cylinder aswell and it almost has 1/8 inch between the ring ends with a ring in the cylinder.

Which one is correct? Thxs.

[KASEY]

didn't you get any paperwork with your piston kit? if not go to there website ,, its only a few thousandths so you need to be sure,,

[Brockey]

Ya I just turned the place upside down and I am guessing the machine shop forgot to give the instructions back.

[Somekindofjerk]

Your ring endgap according to the manual should be .2mm-.4mm

And piston to cylinder should be .060mm-.095mm

[Brockey]

Well that sounds about right then. I dont know which way the arrow should point on the piston. Towards the card or exhaust?

[Somekindofjerk]

To the front of the engine :) (Exhaust)

[Brockey]

Thxs man. I'm gonna go put it together then.

[Somekindofjerk]

Make sure while assembling you use some 2 stroke oil to lube the piston pin and pinbore, rod bearings, and piston/piston rings so it dosnt start dry!

[Brockey]

I used 10w40. Just done that, but its supper time so I cant put the cylinder on until after supper.

[KASEY]

i don't see where you listed the brand of piston you have,,, but quoting specs out of the manual DOES NOT apply to a aftermarket piston,, or rings,,,
is it a cast or forged piston? honda specs do not apply to wiseco or anyother brand ,,, they all have their own specs..................

[Somekindofjerk]

Wiesco calls for .004 for every inch of bore

So the 250R airfoolers are about .010'' ring endgap or .25mm which is still within the manuals spec sheet :)